Define “IR”. Proper night vision uses an image intensifier (the sparkly, grainy image you see in the movies... though it’s less grainy and a blue white colour now), these amplify a wide range of colours from green to into the near infrared. They’ll blow your socks off with what they’ll show outdoors even under heavy tree cover, with no moon away from towns. Most are monocular, there are binocular options, the lower cost models have one intensifier and split the output into two eyepieces... “doing it properly” uses two monoculars bolted together. If one unit is horribly costly, then you can imagine the cost of two... however the contrast boost is impressive (just like using binoculars vs a scope).
If you want to go wildlife watching at night with old fashioned glass binoculars I hope you’ve been eating plenty of carrots as you won’t see a whole lot!
Digital night vision is cheaper, but doesn’t work well when it’s really dark without an “illuminator”... very bright light that’s far enough into the infrared that the camera wi I’ll see it, but you hope the wildlife doesn’t!
If you like looking for warm beasties at night then intensifiers/digital night vision provide no colour information and if stuff isn’t moving about it can be real hard to pick stuff out... however, unless it’s cold blooded it will be warm and so thermal (long wavelength infrared) cameras will show it up nicely... makes it very easy to spot stuff. Thermal isn’t cheap either, but it is more widely available and stuff that’s actually useful is now far more affordable than it was. You can get thermal binoculars, but then they do the same 2eyes from a single detector, so not a true binocular.
Spy.... the right stuff allows you to move about quietly at night without the need for lights, so unless people have similar kit they’ll not know you’re about.
You only really need one eye, keep the other dark adapted to avoid falling over on the dark, unless you are using a 1x monocular in which case you can navigate about in perfect safety. Big vision forums are the best for specific models. Digital mainly need an illuminatkte which needs to be around 900nm to minimise things noticing it. Intensifiers work nicely but you need a high spec one and they cost more.
Agree with wllmspd. I have a IR night vision monocular with x 3 magnification that is quite old ( green/ black ) image. Fine at the time, 10 years ago......generation 2. Useful on clear starry nights but when overcast the IR was essential. Deer, rabbits, hares, owls and bats all located using it.
But things have improved substantially and it is really a question of budget, budget and budget. Tested out binocular/ goggles but I couldn't walk properly using them for fear of falling over.
You need to consider how often, and what image you're seeking.
Helmet / head mounted IR Nightvision binoculars will take some getting used to and most certainly will draw attention to yourself by passers by and most likely the local police dependant on the scenario ( when and where you are wearing them ). I recall vividly observing a group of "poachers" in pitch black darkness for 5 minutes before they thankfully went past..... I switched off the IR lightbeam to avoid detection. Carrying guns in their vehicle as well as dogs.
Again, another reason to consider a hand held monocular which can be carried conveniently in a large pocket.
Head mount really means helmet, the head strap option is probably referred to as a “skull crusher” for a good reason. Walking about with 1x is fine. I have mine on a binocular strap so I can swing it up and down as needed, or use a wrist strap so I can use it when needed. Gen3 has existed for 25+yrs, slowly improving. The issue is availability which impacts on price. Second hand stuff on the US is very reasonable. There are now EU manufacturers, but the costs are still very high. A reasonable gen2 or a reasonable digital aided by a 900nm flashlight is probably a reasonable entry level, but don’t expect miracles. Try to keep to low magnification, with all NV the key is to cram as many photons in the detector as possible, which means fast f-ratios and hence low powers (or huge lenses). Magnification might make things bigger, but it also makes them dimmer, which is the opposite of what you want. If you want more detail you will need to get closer.